I've tried everything I can think of/find to hide the status bar on iOS 7, but after the launch it appears:
//in viewDidLoad
[[UIApplication sharedApplication] setStatusBarHidden:YES withAnimation:UIStatusBarAnimationFade];
//in the main view controller
- (BOOL)prefersStatusBarHidden
{
return YES;
}
I also set "Status bar is initially hidden", and "View controller-based status bar appearance" to YES in the info.plist.
Oddly, the status bar does hide after another controller appears, like a picker or the keyboard.